[PATCH v2 3/3] arm64: dts: freescale: imx95-toradex-smarc: Use gpio-hog for WIFI_UART_EN

[Franz Schnyder]

From: Franz Schnyder <franz.schnyder at toradex.com>

On the Toradex SMARC iMX95, the WiFi UART signals are shared with the
JTAG. The WIFI_UART_EN signal is used to select between these
two functions. A GPIO hog is used to select the UART function by
default. This DT file is going to be used by both Linux and the boot
firmware, and the boot firmware will configure the GPIO hog way before
the Linux kernel is booted, therefore there is no actual race condition
between the Linux kernel BT UART driver and GPIO hog probe.

Configure WIFI_UART_EN as a gpio-hog driven high.

Signed-off-by: Franz Schnyder <franz.schnyder at toradex.com>
---
v2: Remove unused label for wifi-uart-en-hog node
    Add explanation to clarify the safe usage of the GPIO hog
---
 arch/arm64/boot/dts/freescale/imx95-toradex-smarc.dtsi | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/arm64/boot/dts/freescale/imx95-toradex-smarc.dtsi b/arch/arm64/boot/dts/freescale/imx95-toradex-smarc.dtsi
index a90edefc5197..8eef26eb0f87 100644
--- a/arch/arm64/boot/dts/freescale/imx95-toradex-smarc.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx95-toradex-smarc.dtsi
@@ -451,6 +451,13 @@ som_gpio_expander_1: gpio at 21 {
 			"",
 			"",
 			"SMARC_SDIO_WP";
+
+		wifi-uart-en-hog {
+			gpio-hog;
+			gpios = <12 GPIO_ACTIVE_HIGH>;
+			line-name = "WIFI_UART_EN";
+			output-high;
+		};
 	};
 
 	embedded-controller at 28 {
-- 
2.43.0